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We describe the application of the dual boundary element method for the determination of stress intensity factors in plate bending problems. The loadings considered include internal pressure, and also combined bending and tension. Mixed mode stress intensity factors are evaluated by a crack surface displacement extrapolation technique and the J-integral technique. The boundary element results for the case studies considered in the paper have been compared with either analytical or finite element results and in all cases good agreement has been achieved. [ABSTRACT FROM AUTHOR]

This paper considers the basic principles of the most widespread methods for determining typical states of a mode I through crack in specimens and structures of sheet metals that are fractured under conditions close to the plane stress state. The results of experimental investigations are presented which make it possible to judge of the relative advantages and disadvantages of these methods from the standpoint of their possible use in engineering assessments of the integrity and remaining strength of thin-wall structures. [ABSTRACT FROM AUTHOR]

The paper addresses the well-known (from available publications) phenomenological strength criteria for anisotropic materials, which are most widely used in application software. [ABSTRACT FROM AUTHOR]

We review the currently available approaches, applicable codes and standards for assessment of defects in trunk pipelines and discuss advantages and disadvantages of the National pipeline regulations. The paper outlines the main principles of the newly introduced normative document that regulates the assessment of strength and remaining life of pipelines containing service defects. [ABSTRACT FROM AUTHOR]

The paper gives the research findings which make it possible to construct an algorithm for the residual life assessment within the framework of a tensor approach to describing damage in a material under inelastic deformation. The authors propose explicit finite criterial relationships for the residual life assessment, which extend the known relationships to cover a wider range of loading processes. [ABSTRACT FROM AUTHOR]

The paper considers interrelation between the regularities in the fatigue fracture and inelastic deformation taking into account the material properties, stress gradient and concentration, specimen size, load cycle asymmetry, complex stress state, temperature, loading frequency and conditions, scatter of the test results. Analysis of the data from the literature and results of original investigations has shown that the characteristics of inelasticity, which define nonlocalized fatigue damage, can be used in studies of general regularities of the high-cycle fatigue fracture. Specific results of such analysis are presented. [ABSTRACT FROM AUTHOR]

We review the currently available methods that are used to explain the difference in fatigue strength of metals and alloys under conditions of uniform and nonuniform stressed states. We discuss (i) the empirical methods, (ii) the methods allowing for the difference between nominal and effective cyclic stresses, (iii) the methods based on the notions of statistical theories of strength, and (iv) the methods assuming that responsible for fatigue failure are the averaged stresses in the surface layer. The calculated results are verified against experimental findings. [ABSTRACT FROM AUTHOR]

Holding periods of 300 and 3600 s in a trapezoidal load cycle are shown to increase the crack growth rate dozens of times for alloy ÉP962 and several-fold for alloy ÉP742 at a temperature of 973 K. It is demonstrated that in the presence of the first portion on the creep crack growth diagram, whereon the crack growth rate decreases, the crack growth kinetics for a trapezoidal load cycle can be predicted using the hypothesis of the linear summation of fatigue and creep crack growth rates provided that the peculiarities of the first portion of the creep crack growth diagram are taken into account. Empirical approaches are proposed for determining the mean crack velocity in the first portion of the creep crack growth diagram. [ABSTRACT FROM AUTHOR]

The regularities of the scatter in the characteristics of fatigue and inelasticity of steels 45 and 1Kh13 have been studied under steady-state, step, and block loading. It is shown that the use of the inelastic strain per cycle as a measure of the fatigue damage accumulation rate makes it possible to take into account the scatter in the number of cycles to fracture and in the fatigue limits and to substantiate the cumulative fatigue damage rule. [ABSTRACT FROM AUTHOR]

New methods to formulate fracture mechanics parameters are presented. These include the common format that relates the deformation behavior of a cracked structure or specimen to the deformation behavior of a tensile test and the concise format that suggests a shortened form of common fracture mechanics parameters to replace the usual polynomial formulations. These forms may give an easier way to use the fracture mechanics parameters in analytical calculations. [ABSTRACT FROM AUTHOR]

Hold times of 300 and 3600 s under trapezoidal cyclic loading are shown to result in an increase in crack growth rates by many factors of ten for EP962 alloy and several times for EP742 alloy at a temperature 973 K. It has been found that in case the creep crack growth diagram has a first segment where the crack growth rate decreases, the crack growth kinetics under trapezoidal cyclic loading can be predicted by means of the hypothesis of linear summation of fatigue and creep crack growth rates considering special features of the first segment of the creep crack growth diagram. The authors put forward empirical approaches to determining the mean rate on the first segment of the creep crack growth diagram. [ABSTRACT FROM AUTHOR]

Using the Unified Curve method as proposed by the authors earlier and a probabilistic model based on the local approach and physical background of the influence of impurities and carbide size on the local strength of material, a method has been elaborated for predicting a variation of the temperature dependence of fracture toughness with neutron fluence. The results calculated by this method are compared to the available experimental data. [ABSTRACT FROM AUTHOR]

The authors consider the influence of temperature, load cycle asymmetry, specimen size, plastic prestraining, and material damage in the course of low-cycle loading on the magnitude of fatigue fracture toughness of heat resistant, high-strength chrome-molybdenum and other steels. They analyze the degree of this influence depending on various factors varied in the process of investigation. [ABSTRACT FROM AUTHOR]